@Blort : Thanks Blort
@valerydesignwrks : I would recommend https://krita-artists.org/ , a forum around the digital free/libre and open source software Krita.
It's not for professional only, but I don't know any groups or hashtags that triage the users making a main source of income with their art and the one who prefer to keep it as a hobby. Hashtag like MastoArt can help the discovery of profiles, but you'll have to check bios for the pro/hobby status.
@davidrevoy @Blort @sylvia_ritter @Curator @editor Thanks for your reply.
@davidrevoy @Blort @valerydesignwrks I agree, the krita-artists.org forum is also great .